Madrigal Pharmaceuticals (MDGL) 10-Q 7 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	1-May-15
Document and Entity Information
Entity Registrant Name	SYNTA PHARMACEUTICALS CORP
Entity Central Index Key	1157601
Document Type	10-Q
Document Period End Date	31-Mar-15
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		134,420,670
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$33,255	$46,024
Marketable securities	43,351	51,666
Prepaid expenses and other current assets	1,367	1,656
Total current assets	77,973	99,346
Property and equipment, net	855	1,024
Other assets	564	305
Total assets	79,392	100,675
Current liabilities:
Accounts payable	3,738	3,139
Accrued contract research costs	12,511	12,317
Other accrued liabilities	5,408	6,177
Current portion of capital lease obligations	42	42
Current portion of term loans	9,221	9,214
Total current liabilities	30,920	30,889
Long-term liabilities:
Capital lease obligations, net of current portion	33	43
Term loans, net of current portion	2,299	4,607
Total long-term liabilities	2,332	4,650
Total liabilities	33,252	35,539
Stockholders' equity:
Preferred stock, par value $0.0001 per share Authorized: 5,000,000 shares at March 31, 2015 and December 31, 2014; no shares issued and outstanding at each of March 31, 2015 and December 31, 2014
Common stock, par value $0.0001 per share Authorized: 200,000,000 shares at March 31, 2015 and December 31, 2014; 109,120,670 shares issued and outstanding at each of March 31, 2015 and December 31, 2014	11	11
Additional paid-in-capital	704,403	702,694
Accumulated other comprehensive income	6	4
Accumulated deficit	-658,280	-637,573
Total stockholders' equity	46,140	65,136
Total liabilities and stockholders' equity	$79,392	$100,675

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Condensed Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, Authorized shares	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, Authorized shares	200,000,000	200,000,000
Common stock, shares issued	109,120,670	109,120,670
Common stock, shares outstanding	109,120,670	109,120,670

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating expenses:
Research and development	$16,182	$17,583
General and administrative	4,150	5,324
Total operating expenses	20,332	22,907
Loss from operations	-20,332	-22,907
Interest expense, net	-375	-650
Net loss	($20,707)	($23,557)
Net loss per common share:
Basic and diluted net loss per common share (in dollars per share)	($0.19)	($0.28)
Basic and diluted weighted average number of common shares outstanding	108,376,264	85,438,127

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Condensed Consolidated Statements of Comprehensive Loss
Net loss	($20,707)	($23,557)
Other comprehensive (loss):
Unrealized gain (loss) on available-for-sale securities	2	-13
Comprehensive loss	($20,705)	($23,570)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net loss	($20,707)	($23,557)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,710	2,586
Depreciation and amortization	169	168
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	289	153
Other assets	-259	32
Accounts payable	598	-780
Accrued contract research costs	194	2,081
Other accrued liabilities	-769	-953
Net cash used in operating activities	-18,775	-20,270
Cash flows from investing activities:
Purchases of marketable securities	-28,683	-3,548
Maturities of marketable securities	37,000	19,768
Purchases of property and equipment		-23
Net cash provided by investing activities	8,317	16,197
Cash flows from financing activities:
Proceeds from issuance of common stock, net of transaction costs, and exercise of common stock options		10,118
Payment of term loans	-2,301	-2,490
Payment of capital lease obligations	-10	-11
Net cash (used in) provided by financing activities	-2,311	7,617
Net (decrease) increase in cash and cash equivalents	-12,769	3,544
Cash and cash equivalents at beginning of period	46,024	48,490
Cash and cash equivalents at end of period	33,255	52,034
Supplemental disclosure of cash flow information:
Cash paid for interest	$325	$560

Nature_of_Business

Nature of Business	3 Months Ended
	Mar. 31, 2015
Nature of Business
Nature of Business
	(1) Nature of Business
	Synta Pharmaceuticals Corp. (the Company) was incorporated in March 2000 and commenced operations in July 2001. The Company is an innovative, agile biopharmaceutical company focused on research, development and commercialization of novel oncology medicines that have the potential to change the lives of cancer patients.
	The Company is subject to risks common to emerging companies in the drug development and pharmaceutical industry including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, dependence on key personnel, uncertainty of market acceptance of products and product reimbursement, product liability, uncertain protection of proprietary technology, potential inability to raise additional financing and compliance with the U.S. Food and Drug Administration and other government regulations.
	The Company may require significant additional funds earlier than it currently expects in order to conduct additional clinical trials and continue to fund its operations. There can be no assurances, however, that additional funding will be available on favorable terms, or at all. If adequate funds are not available, the Company may be required to delay, significantly modify or terminate its research and development programs or reduce its planned commercialization efforts.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies
	(2) Summary of Significant Accounting Policies
	The accompanying condensed consolidated financial statements are unaudited, have been prepared on the same basis as the annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary to present fairly the Company’s financial position as of March 31, 2015 and the consolidated results of operations, comprehensive loss and cash flows for the three months ended March 31, 2015 and 2014. The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from these estimates. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or any other future year. For more complete financial information, these condensed financial statements, and the notes hereto, should be read in conjunction with the audited financial statements for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K.
	Principles of Consolidation
	The condensed consolidated financial statements include the financial statements of the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect certain reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Significant items subject to such estimates and assumptions include contract research accruals, recoverability of long-lived assets, measurement of stock-based compensation, and the periods of performance under collaborative research and development agreements. The Company bases its estimates on historical experience and various other assumptions that management believes to be reasonable under the circumstances. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase and an investment in a money market fund to be cash equivalents. Changes in the level of cash and cash equivalents may be affected by changes in investment portfolio maturities, as well as actual cash disbursements to fund operations.
	The primary objective of the Company’s investment activities is to preserve its capital for the purpose of funding operations and the Company does not enter into investments for trading or speculative purposes. The Company’s cash is deposited in a highly rated financial institution in the United States. The Company invests in money market funds and high-grade, short-term commercial paper and corporate bonds, which management believes are subject to minimal credit and market risk. Declines in interest rates, however, would reduce future investment income.
	Marketable Securities
	Marketable securities consist of investments in high-grade corporate obligations, and government and government agency obligations that are classified as available-for-sale. Since these securities are available to fund current operations they are classified as current assets on the consolidated balance sheets.
	The Company adjusts the cost of available-for-sale debt securities for amortization of premiums and accretion of discounts to maturity. The Company includes such amortization and accretion as a component of interest expense, net. Realized gains and losses and declines in value, if any, that the Company judges to be other-than-temporary on available-for-sale securities are reported as a component of interest expense, net. To determine whether an other-than-temporary impairment exists, the Company considers whether it intends to sell the debt security and, if the Company does not intend to sell the debt security, it considers available evidence to assess whether it is more likely than not that it will be required to sell the security before the recovery of its amortized cost basis. During the three months ended March 31, 2015 and 2014, the Company determined it did not have any securities that were other-than-temporarily impaired.
	Marketable securities are stated at fair value, including accrued interest, with their unrealized gains and losses included as a component of accumulated other comprehensive income or loss, which is a separate component of stockholders’ equity. The fair value of these securities is based on quoted prices and observable inputs on a recurring basis. Realized gains and losses are determined on the specific identification method. During the three months ended March 31, 2015 and 2014, the Company did not have any realized gains or losses on marketable securities.
	Fair Value of Financial Instruments
	The carrying amounts of the Company’s financial instruments, which include cash equivalents, marketable securities and term loan obligations, approximate their fair values. The fair value of the Company’s financial instruments reflects the amounts that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy has the following three levels:
	Level 1—quoted prices in active markets for identical assets and liabilities.
	Level 2—observable inputs other than Level 1 inputs. Examples of Level 2 inputs include quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active.
	Level 3—unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability.
	Financial assets and liabilities are classified in their entirety within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The Company measures the fair value of its marketable securities by taking into consideration valuations obtained from third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker-dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities and other observable inputs. As of March 31, 2015, the Company’s financial assets valued based on Level 1 inputs consisted of cash and cash equivalents in a money market fund and its financial assets valued based on Level 2 inputs consisted of high-grade corporate bonds and commercial paper. During the three months ended March 31, 2015 and 2014, the Company did not have any transfers of financials assets between Levels 1 and 2. As of March 31, 2015, the Company did not have any financial liabilities that were recorded at fair value on the balance sheet. The disclosed fair value of the Company’s term loan obligations is determined using current applicable rates for similar instruments as of the balance sheet date. The carrying value of the Company’s term loan obligations approximates fair value as the Company’s interest rate yield is near current market rate yields. The disclosed fair value of the Company’s term loan obligations is based on Level 3 inputs.
	Revenue Recognition
	Collaboration and License Agreements
	The Company’s principal source of revenue to date has been its former collaboration and license agreements, which included upfront license payments, development milestones, reimbursement of research and development costs, potential profit sharing payments, commercial and sales-based milestones and royalties. The accounting for collaboration and license agreements requires subjective analysis and requires management to make estimates and assumptions about whether deliverables within multiple-element arrangements are separable from the other aspects of the contractual arrangement into separate units of accounting and to determine the arrangement consideration to be allocated to each unit of accounting.
	For multiple-element arrangements entered into or materially modified after January 1, 2011, the Company follows the provisions of Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2009-13— Multiple-deliverable Revenue Arrangements (ASU No. 2009-13). ASU No. 2009-13 amended certain provisions of Accounting Standards Codification (ASC) Topic 605— Revenue Recognition. This standard addresses the determination of the unit(s) of accounting for multiple-element arrangements and how an arrangement’s consideration should be allocated to each unit of accounting.
	Pursuant to this standard, each required deliverable is evaluated to determine if it qualifies as a separate unit of accounting. For the Company this determination includes an assessment as to whether the deliverable has “stand-alone value” to the customer separate from the undelivered elements. The arrangement’s consideration is then allocated to each separate unit of accounting based on the relative selling price of each deliverable. The estimated selling price of each deliverable is determined using the following hierarchy of values: (i) vendor-specific objective evidence of fair value, (ii) third-party evidence of selling price, or (iii) the Company’s best estimate of the selling price (BESP). The BESP reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold by it on a stand-alone basis. The Company expects, in general, to use BESP for allocating consideration to each deliverable in future collaboration agreements. In general, the consideration allocated to each unit of accounting is then recognized as the related goods or services are delivered limited to the consideration not contingent upon future deliverables. The Company did not recognize any revenue related to collaboration and license agreements during the three months ended March 31, 2015 and 2014.
	The Company accounts for development milestones under collaboration and license agreements pursuant to ASU No. 2010-17Milestone Method of Revenue Recognition (ASU No. 2010-17). ASU No. 2010-17 codified a method of revenue recognition that has been common practice. Under this method, contingent consideration from research and development activities that is earned upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, clinical, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment. The Company does not have any ongoing collaboration and license agreements under which milestones may be achieved.
	Royalty revenues are based upon a percentage of net sales. Royalties from the sales of products will be recorded on the accrual basis when results are reliably measurable, collectability is reasonably assured and all other revenue recognition criteria are met. Commercial and sales-based milestones, which are based upon the achievement of certain agreed-upon sales thresholds, will be recognized in the period in which the respective sales threshold is achieved and collectability is reasonably assured. The Company does not have any ongoing collaboration and license agreements under which royalties or commercial and sales-based milestones may be achieved.
	Stock-Based Compensation
	The Company recognizes stock-based compensation expense based on the grant date fair value of stock options granted to employees, officers and directors. The Company uses the Black-Scholes option pricing model to determine the grant date fair value as management believes it is the most appropriate valuation method for its option grants. The Black-Scholes model requires inputs for risk-free interest rate, dividend yield, volatility and expected lives of the options. Expected volatility is based upon the weighted average historical volatility data of the Company’s common stock. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. The expected lives for options granted represent the period of time that options granted are expected to be outstanding. The Company uses the simplified method for determining the expected lives of options. The Company estimates the forfeiture rate based on historical data. This analysis is re-evaluated at least annually and the forfeiture rate is adjusted as necessary.
	For awards with graded vesting, the Company recognizes compensation costs based on the grant date fair value of awards on a straight-line basis over the requisite service period, which is generally the vesting period.
	Certain of the employee stock options granted by the Company are structured to qualify as incentive stock options (ISOs). Under current tax regulations, the Company does not receive a tax deduction for the issuance, exercise or disposition of ISOs if the employee meets certain holding requirements. If the employee does not meet the holding requirements, a disqualifying disposition occurs, at which time the Company may receive a tax deduction. The Company does not record tax benefits related to ISOs unless and until a disqualifying disposition is reported. In the event of a disqualifying disposition, the entire tax benefit is recorded as a reduction of income tax expense. The Company has not recognized any income tax benefit for its share-based compensation arrangements due to the fact that the Company does not believe it is more likely than not it will realize the related deferred tax assets.
	Comprehensive Loss
	Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Changes in unrealized gains and losses on marketable securities represent the only difference between the Company’s net loss and comprehensive loss.
	Segment Reporting
	Operating segments are determined based on the way management organizes its business for making operating decisions and assessing performance. The Company has a single operating segment, which is the discovery, development and commercialization of drug products.
	Basic and Diluted Loss Per Common Share
	Basic net loss per share is computed using the weighted average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per common share is computed using the weighted average number of common shares outstanding and the weighted average dilutive potential common shares outstanding using the treasury stock method. However, for the three months ended March 31, 2015 and 2014, diluted net loss per share is the same as basic net loss per share as the inclusion of weighted average shares of unvested restricted common stock and common stock issuable upon the exercise of stock options would be anti-dilutive.
	The following table summarizes outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive:
		March 31,
		2015	2014
	Common stock options	10,123,204	8,179,958
	Unvested restricted common stock	734,758	35,000
	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU No. 2014-09, —Revenue from Contracts with Customers (Topic 606), which amends the guidance for accounting for revenue from contracts with customers. This ASU supersedes the revenue recognition requirements in ASC Topic 605, and creates a new Topic 606, Revenue from Contracts with Customers. This guidance is effective for fiscal years beginning after December 15, 2016, with early adoption not permitted. Two adoption methods are permitted: retrospectively to all prior reporting periods presented, with certain practical expedients permitted; or retrospectively with the cumulative effect of initially adopting the ASU recognized at the date of initial application. In April 2015, the FASB proposed a one year deferral of the effective date of this standard to annual periods ending after December 15, 2017, along with an option to permit companies to early adopt the standard for annual periods beginning after December 15, 2016. The Company has not yet determined which adoption method it will utilize or the effect that the adoption of this guidance will have on its consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15, —Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. This ASU is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years ending after December 15, 2016, with early application permitted. The Company has not yet determined the effect that the adoption of this guidance will have on the disclosures included in its consolidated financial statements.

Cash_Cash_Equivalents_and_Mark

Cash, Cash Equivalents and Marketable Securities	3 Months Ended
	Mar. 31, 2015
Cash, Cash Equivalents and Marketable Securities
Cash, Cash Equivalents and Marketable Securities
	(3) Cash, Cash Equivalents and Marketable Securities
	A summary of cash, cash equivalents and available-for-sale marketable securities held by the Company as of March 31, 2015 and December 31, 2014 was as follows in thousands (see Note 2):
		March 31, 2015
		Cost		Unrealized		Unrealized			Fair
				gains		losses			value
	Cash and cash equivalents:
	Cash and money market funds (Level 1)	$	21,720	$	—	$	—		$	21,720
	Corporate debt securities due within 3 months of date of purchase (Level 2)	11,535		—		—			11,535
	Total cash and cash equivalents	$	33,255	$	—	$	—		$	33,255
	Marketable securities:
	Corporate debt securities due within 1 year of date of purchase (Level 2)	43,345		11		(5		)	43,351
	Total cash, cash equivalents and marketable securities	$	76,600	$	11	$	(5	)	$	76,606
		December 31, 2014
		Cost		Unrealized		Unrealized			Fair
				gains		losses			value
	Cash and cash equivalents:
	Cash and money market funds (Level 1)	$	45,004	$	—	$	—		$	45,004
	Corporate debt securities due within 3 months of date of purchase (Level 2)	1,020		—		—			1,020
	Total cash and cash equivalents	$	46,024	$	—	$	—		$	46,024
	Marketable securities:
	Corporate debt securities due within 1 year of date of purchase (Level 2)	51,662		12		(8		)	51,666
	Total cash, cash equivalents and marketable securities	$	97,686	$	12	$	(8	)	$	97,690

Property_and_Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2015
Property and Equipment
Property and Equipment
	(4) Property and Equipment
	Property and equipment as of March 31, 2015 and December 31, 2014 consisted of the following (in thousands):
		March 31,			December 31,
		2015			2014
	Laboratory equipment	$	12,217		$	12,217
	Leasehold improvements	4,988			4,988
	Computers and software	3,126			3,126
	Furniture and fixtures	1,176			1,176
		21,507			21,507
	Less accumulated depreciation and amortization	(20,652		)	(20,483		)
		$	855		$	1,024
	Depreciation and amortization expenses of property and equipment, including equipment purchased under capital leases, were approximately $0.2 million in each of the three months ended March 31, 2015 and 2014.

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2015
Stockholders' Equity
Stockholders' Equity
	(5) Stockholders’ Equity
	Common Stock
	Each common stockholder is entitled to one vote for each common share of stock held. The common stock will vote together with all other classes and series of stock of the Company as a single class on all actions to be taken by the Company’s stockholders. Each share of common stock is entitled to receive dividends, as and when declared by the Company’s board of directors.
	The Company has never declared cash dividends on its common stock and does not expect to do so in the foreseeable future.
	At-The-Market Issuance Sales Agreement
	In July 2014, the Company entered into an at-the-market issuance sales agreement (July 2014 Sales Agreement) with MLV & Co. LLC (MLV), pursuant to which the Company may issue and sell shares of its common stock from time to time, at the Company’s option, through MLV as its sales agent. Sales of common stock through MLV may be made by any method that is deemed an “at-the-market” offering as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, including by means of ordinary brokers’ transactions at market prices, in block transactions or as otherwise agreed by the Company and MLV. Subject to the terms and conditions of the Sales Agreement, MLV will use commercially reasonable efforts to sell the common stock based upon the Company’s instructions (including any price, time or size limits or other customary parameters or conditions the Company may impose). The Company is not obligated to make any sales of its common stock under the Sales Agreement. Any shares sold will be sold pursuant to an effective shelf registration statement on Form S-3. The Company will pay MLV a commission of up to 3% of the gross proceeds. The July 2014 Sales Agreement may be terminated by the Company at any time.
	In July 2014, the Company reserved up to $50 million under its shelf registration statement for issuance under the July 2014 Sales Agreement. In the third quarter of 2014, the Company sold an aggregate of 5,679,685 shares of common stock pursuant to the July 2014 Sales Agreement for an aggregate of approximately $23.0 million in gross proceeds at an average selling price of $4.05 per share. Net proceeds to the Company were approximately $22.5 million after deducting commissions and other transaction costs. As of March 31, 2015, approximately $27.0 million remained reserved under the Company’s shelf registration statement and the applicable prospectus supplement for possible future issuance under the July 2014 Sales Agreement.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation
Stock-Based Compensation
	(6) Stock-Based Compensation
	The Company’s 2006 Stock Plan provides for the grant of incentive stock options, non-statutory stock options and non-vested restricted stock to employees, officers, directors and consultants of the Company. In January 2015, the number of shares of common stock reserved for issuance under the 2006 Stock Plan was increased from 10,300,000 to 11,600,000 pursuant to an “evergreen” provision, which provides for an annual increase based on the lesser of 1,300,000 shares, 5% of the Company’s then outstanding shares of common stock, or such other amount as the board of directors may determine. This increase was approved by the board of directors in December 2014. The administration of the 2006 Stock Plan is under the general supervision of the compensation committee of the board of directors. The exercise price of the stock options is determined by the compensation committee of the board of directors, provided that incentive stock options are granted with an exercise price not less than fair market value of the common stock on the date of grant and expire no later than ten years from the date the option is granted. Options generally vest over four years. As of March 31, 2015, the Company had options outstanding to purchase 10,123,204 shares of its common stock, which includes options outstanding under its 2001 Stock Plan that was terminated in March 2006. As of March 31, 2015, 1,261,136 shares were available for future issuance.
	The following table summarizes stock option activity during the three months ended March 31, 2015:
		Shares		Weighted average
				exercise price
				per share
	Outstanding at January 1, 2015	8,829,343		$	6.17
	Options granted	1,693,686		2.39
	Options exercised	—		—
	Options cancelled	(399,825	)	9.14
	Outstanding at March 31, 2015	10,123,204		$	5.42
	Exercisable at March 31, 2015	5,305,790		$	6.45
	The total cash received by the Company as a result of stock option exercises during the three months ended March 31, 2015 and 2014 was $0 and $0.8 million, respectively. The weighted-average grant date fair values of options granted during the three months ended March 31, 2015 and 2014 were $1.92 and $5.02, respectively.
	Non-Vested (“Restricted”) Stock Awards With Service Conditions
	The Company’s share-based compensation plan provides for awards of restricted shares of common stock to employees, officers, directors and consultants to the Company. Restricted stock awards are subject to forfeiture if employment or service terminates during the prescribed retention period. Restricted shares vest over the service period. The total fair value of restricted stock that vested in each of the three months ended March 31, 2015 and 2014 was $0.1 million.
	The following table summarizes unvested restricted share activity during the three months ended March 31, 2015:
		Shares		Weighted
				average
				grant date
				fair value
				per share
	Outstanding at January 1, 2015	744,514		$	3.65
	Vested	(9,756	)	4.1
	Granted	—		—
	Forfeited	—		—
	Outstanding at March 31, 2015	734,758		$	3.65
	Stock-Based Compensation Expense
	For the three months ended March 31, 2015 and 2014, the fair value of each employee stock option award was estimated on the date of grant based on the fair value method using the Black-Scholes option pricing valuation model with the following weighted average assumptions:
		Three Months
		Ended March 31,
		2015		2014
	Risk-free interest rate	1.77	%	1.84	%
	Expected life in years	6.25		6.25
	Volatility	101	%	104	%
	Expected dividend yield	—		—
	Stock-based compensation expense during the three months ended March 31, 2015 and 2014 was as follows (in thousands):
		Three Months
		Ended March 31,
		2015			2014
	Stock-based compensation expense by type of award:
	Employee stock options	$	1,508		$	2,529
	Restricted stock	202			57
	Total stock-based compensation expense	$	1,710		$	2,586
	Effect of stock-based compensation expense by line item:
	Research and development	$	981		$	1,131
	General and administrative	729			1,455
	Total stock-based compensation expense included in net loss	$	1,710		$	2,586
	Unrecognized stock-based compensation expense as of March 31, 2015 was as follows (dollars in thousands):
		Unrecognized			Weighted
		stock			average
		compensation			remaining
		expense			period
					(in years)
	Employee stock options	$	13,821		2.79
	Restricted stock	2,343			3.19
	Total	$	16,164		2.85

Other_Accrued_Liabilities

Other Accrued Liabilities	3 Months Ended
	Mar. 31, 2015
Other Accrued Liabilities
Other Accrued Liabilities
	7) Other Accrued Liabilities
	Other accrued liabilities as of March 31, 2015 and December 31, 2014 consisted of the following (in thousands):
		March 31,		December 31,
		2015		2014
	Compensation and benefits	$	2,605	$	3,852
	Professional fees	1,696		1,285
	Other	1,107		1,040
		$	5,408	$	6,177

CoDevelopment_and_License_Agre

Co-Development and License Agreements	3 Months Ended
	Mar. 31, 2015
Co-Development and License Agreements
Co-Development and License Agreements
	(8) Co-Development and License Agreements
	Co-Development Agreement
	In July 2011, the Company entered into a co-development agreement with a clinical research organization (CRO) for the conduct of certain company-sponsored clinical trials. Under the co-development agreement, this CRO was performing clinical research services under a reduced fee structure in exchange for a share of licensing payments and commercial revenues, if any, resulting from the product under development up to a specified maximum payment, which is defined as a multiple of the fee reduction realized. Research and development expenses were being recognized based on the reduced fee structure and expected payments will be recorded in the future if and when payment is probable. The maximum amount of the service fee discount was realized in the year ended December 31, 2013.
	License Arrangement
	In May 2014, the Company entered into a license arrangement for its CRACM program, including two lead candidates and the associated intellectual property portfolio, with PRCL Research Inc. (PRCL), a company funded by TVM Life Science Venture VII and the Fonds de Solidarité des Travailleurs du Québec, based in Montreal, Canada. PRCL plans to develop one of the two lead candidates licensed from the Company to proof-of-concept. Synta was granted a minority interest in PRCL in exchange for its contribution of know-how and intellectual property and will also hold a seat on PRCL’s Board of Directors. Synta will not be required to provide any research funding or capital contributions to PRCL. Synta will be reimbursed by PRCL for any ongoing intellectual property management costs in connection with the contributed intellectual property and may conduct preclinical research activities which would be reimbursed by PRCL. If and when proof-of-concept is reached with either drug candidate, Eli Lilly and Company, which is an investor in TVM, will manage the development program through one of its divisions and will have an option to acquire PRCL or its assets at the then fair value.

Term_Loans

Term Loans	3 Months Ended
	Mar. 31, 2015
Term Loans
Term Loans
	(9) Term Loans
	General Electric Capital Corporation
	In March 2013, the Company amended its loan and security agreement entered into in September 2010 with General Electric Capital Corporation (GECC) and another lender (the GECC Term Loan) and obtained $12.9 million in additional loan funding and, as a result, increased the principal balance to $22.5 million at March 31, 2013. This amendment was accounted for as a loan modification. Interest on the borrowings under the GECC Term Loan remains at the annual rate of 9.75%. In January 2014, the Company began making 30 equal monthly payments of principal plus accrued interest on the outstanding balance. During the period from July 2012 through March 2013, the Company made nine equal monthly payments of principal under the GECC Term Loan. For the periods from April 2013 through December 2013 and prior to July 2012 the Company made interest-only payments.
	The Company has paid various transaction fees and expenses in connection with the GECC Term Loan, which are deferred and are being amortized as interest expense over the remaining term of the GECC Term Loan. In addition, the Company is obligated to pay an exit fee of $788,000 at the time of the final principal payment which is being accreted and expensed as interest over the remaining term of the GECC Term Loan. In the three months ended March 31, 2015 and 2014, the Company recognized GECC Term Loan interest expense of $0.4 million and $0.6 million, respectively, of which $0.1 million was in connection with these transaction and exit fees and expenses in each of the periods. The Company may prepay the full amount of the GECC Term Loan, subject to prepayment premiums under certain circumstances. The Company did not issue any warrants in connection with the GECC Term Loan.
	The GECC Term Loan is secured by substantially all of the Company’s assets, except its intellectual property. The Company has granted GECC a springing security interest in its intellectual property in the event the Company is not in compliance with certain cash usage covenants, as defined therein. The GECC Term Loan contains restrictive covenants, including the requirement for the Company to receive the prior written consent of GECC to enter into loans, other than up to $4.0 million of equipment financing, restrictions on the declaration or payment of dividends, restrictions on acquisitions, and customary default provisions that include material adverse events, as defined therein. The Company has determined that the risk of subjective acceleration under the material adverse events clause is remote and therefore has classified the outstanding principal in current and long-term liabilities based on the timing of scheduled principal payments.
	Oxford Finance Corporation
	In March 2011, the Company entered into a loan and security agreement with Oxford Finance Corporation (Oxford) and received $2.0 million in loan funding, and in December 2012, the Company entered into a loan modification agreement, as amended, under which the Company could elect to draw down up to an additional $0.6 million in equipment financing until June 30, 2013 that would be payable in 36 equal monthly payments of principal plus accrued interest on the outstanding balance (collectively, the Oxford Term Loan). As of June 30, 2013, the Company had fully utilized the $0.6 million in additional equipment financing. Interest on the borrowings under the Oxford Term Loan accrues at an annual rate of 13.35%. In May 2011, the Company began making 36 equal monthly payments of principal plus accrued interest on the initial $2.0 million outstanding balance that was fully paid in April 2014. The Company continues to make equal monthly payments of principal plus accrued interest on the $0.6 million in additional equipment financing. The Company recognized approximately $13,000 and $20,000 in interest expense in the three months ended March 31, 2015 and 2014, respectively, related to the outstanding principal under the Oxford Term Loan. In addition to the interest payable under the Oxford Term Loan, the Company paid approximately $108,000 of administrative and legal fees and expenses in connection with the Oxford Term Loan. These expenses have been deferred and are being expensed over the term of the Oxford Term Loan. The Company did not issue any warrants in connection with the Oxford Term Loan. The Company may prepay the Oxford Term Loan, subject to prepayment premiums under certain circumstances. Oxford has the right to require the Company to prepay the Oxford Term Loan if the Company prepays the full amount of the GECC Term Loan under certain circumstances.
	The Oxford Term Loan is secured by certain laboratory and office equipment, furniture and fixtures. In connection with the Oxford Term Loan, Oxford and GECC entered into a Lien Subordination Agreement, whereby GECC granted Oxford a first priority perfected security interest in the loan collateral. The Oxford Term Loan contains restrictive covenants, including the requirement for the Company to receive the prior written consent of Oxford to enter into acquisitions in which the Company incurs more than $2.0 million of related indebtedness, and customary default provisions that include material adverse events, as defined therein. The Company has determined that the risk of subjective acceleration under the material adverse events clause is remote and therefore has classified the outstanding principal in current and long-term liabilities based on the timing of scheduled principal payments.
	Future principal payments under the GECC and Oxford Term Loans as of March 31, 2015 were approximately as follows (in thousands):
	Years ending December 31,
	2015	$	6,913
	2016	4,607
	Total principal payments	11,520
	Less current portion	(9,221		)
	Long term portion	$	2,299

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events
Subsequent Events
	(10) Subsequent Events
	Public Offering
	In April 2015, the Company raised approximately $44.3 million in gross proceeds from the sale of an aggregate 25,300,000 shares of its common stock in a public offering at a public offering price of $1.75 per share, including 3,300,000 shares upon the full exercise of the underwriters’ option to purchase additional shares. Certain of the Company’s directors and their affiliates, including its largest stockholder, purchased an aggregate of 7,257,142 shares in this offering at the public offering price. The net offering proceeds to the Company were approximately $41.8 million after deducting underwriters’ discounts, fees and commissions, and other offering expenses payable by the Company.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Summary of Significant Accounting Policies
Principles of Consolidation
	Principles of Consolidation
	The condensed consolidated financial statements include the financial statements of the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates
	Use of Estimates
	The preparation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect certain reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Significant items subject to such estimates and assumptions include contract research accruals, recoverability of long-lived assets, measurement of stock-based compensation, and the periods of performance under collaborative research and development agreements. The Company bases its estimates on historical experience and various other assumptions that management believes to be reasonable under the circumstances. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.
Cash and Cash Equivalents
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase and an investment in a money market fund to be cash equivalents. Changes in the level of cash and cash equivalents may be affected by changes in investment portfolio maturities, as well as actual cash disbursements to fund operations.
	The primary objective of the Company’s investment activities is to preserve its capital for the purpose of funding operations and the Company does not enter into investments for trading or speculative purposes. The Company’s cash is deposited in a highly rated financial institution in the United States. The Company invests in money market funds and high-grade, short-term commercial paper and corporate bonds, which management believes are subject to minimal credit and market risk. Declines in interest rates, however, would reduce future investment income.
Marketable Securities
	Marketable Securities
	Marketable securities consist of investments in high-grade corporate obligations, and government and government agency obligations that are classified as available-for-sale. Since these securities are available to fund current operations they are classified as current assets on the consolidated balance sheets.
	The Company adjusts the cost of available-for-sale debt securities for amortization of premiums and accretion of discounts to maturity. The Company includes such amortization and accretion as a component of interest expense, net. Realized gains and losses and declines in value, if any, that the Company judges to be other-than-temporary on available-for-sale securities are reported as a component of interest expense, net. To determine whether an other-than-temporary impairment exists, the Company considers whether it intends to sell the debt security and, if the Company does not intend to sell the debt security, it considers available evidence to assess whether it is more likely than not that it will be required to sell the security before the recovery of its amortized cost basis. During the three months ended March 31, 2015 and 2014, the Company determined it did not have any securities that were other-than-temporarily impaired.
	Marketable securities are stated at fair value, including accrued interest, with their unrealized gains and losses included as a component of accumulated other comprehensive income or loss, which is a separate component of stockholders’ equity. The fair value of these securities is based on quoted prices and observable inputs on a recurring basis. Realized gains and losses are determined on the specific identification method. During the three months ended March 31, 2015 and 2014, the Company did not have any realized gains or losses on marketable securities.
Fair Value of Financial Instruments
	Fair Value of Financial Instruments
	The carrying amounts of the Company’s financial instruments, which include cash equivalents, marketable securities and term loan obligations, approximate their fair values. The fair value of the Company’s financial instruments reflects the amounts that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy has the following three levels:
	Level 1—quoted prices in active markets for identical assets and liabilities.
	Level 2—observable inputs other than Level 1 inputs. Examples of Level 2 inputs include quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active.
	Level 3—unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability.
	Financial assets and liabilities are classified in their entirety within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement. The Company measures the fair value of its marketable securities by taking into consideration valuations obtained from third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker-dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities and other observable inputs. As of March 31, 2015, the Company’s financial assets valued based on Level 1 inputs consisted of cash and cash equivalents in a money market fund and its financial assets valued based on Level 2 inputs consisted of high-grade corporate bonds and commercial paper. During the three months ended March 31, 2015 and 2014, the Company did not have any transfers of financials assets between Levels 1 and 2. As of March 31, 2015, the Company did not have any financial liabilities that were recorded at fair value on the balance sheet. The disclosed fair value of the Company’s term loan obligations is determined using current applicable rates for similar instruments as of the balance sheet date. The carrying value of the Company’s term loan obligations approximates fair value as the Company’s interest rate yield is near current market rate yields. The disclosed fair value of the Company’s term loan obligations is based on Level 3 inputs.
Revenue Recognition
	Revenue Recognition
	Collaboration and License Agreements
	The Company’s principal source of revenue to date has been its former collaboration and license agreements, which included upfront license payments, development milestones, reimbursement of research and development costs, potential profit sharing payments, commercial and sales-based milestones and royalties. The accounting for collaboration and license agreements requires subjective analysis and requires management to make estimates and assumptions about whether deliverables within multiple-element arrangements are separable from the other aspects of the contractual arrangement into separate units of accounting and to determine the arrangement consideration to be allocated to each unit of accounting.
	For multiple-element arrangements entered into or materially modified after January 1, 2011, the Company follows the provisions of Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2009-13— Multiple-deliverable Revenue Arrangements (ASU No. 2009-13). ASU No. 2009-13 amended certain provisions of Accounting Standards Codification (ASC) Topic 605— Revenue Recognition. This standard addresses the determination of the unit(s) of accounting for multiple-element arrangements and how an arrangement’s consideration should be allocated to each unit of accounting.
	Pursuant to this standard, each required deliverable is evaluated to determine if it qualifies as a separate unit of accounting. For the Company this determination includes an assessment as to whether the deliverable has “stand-alone value” to the customer separate from the undelivered elements. The arrangement’s consideration is then allocated to each separate unit of accounting based on the relative selling price of each deliverable. The estimated selling price of each deliverable is determined using the following hierarchy of values: (i) vendor-specific objective evidence of fair value, (ii) third-party evidence of selling price, or (iii) the Company’s best estimate of the selling price (BESP). The BESP reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold by it on a stand-alone basis. The Company expects, in general, to use BESP for allocating consideration to each deliverable in future collaboration agreements. In general, the consideration allocated to each unit of accounting is then recognized as the related goods or services are delivered limited to the consideration not contingent upon future deliverables. The Company did not recognize any revenue related to collaboration and license agreements during the three months ended March 31, 2015 and 2014.
	The Company accounts for development milestones under collaboration and license agreements pursuant to ASU No. 2010-17Milestone Method of Revenue Recognition (ASU No. 2010-17). ASU No. 2010-17 codified a method of revenue recognition that has been common practice. Under this method, contingent consideration from research and development activities that is earned upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, clinical, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment. The Company does not have any ongoing collaboration and license agreements under which milestones may be achieved.
	Royalty revenues are based upon a percentage of net sales. Royalties from the sales of products will be recorded on the accrual basis when results are reliably measurable, collectability is reasonably assured and all other revenue recognition criteria are met. Commercial and sales-based milestones, which are based upon the achievement of certain agreed-upon sales thresholds, will be recognized in the period in which the respective sales threshold is achieved and collectability is reasonably assured. The Company does not have any ongoing collaboration and license agreements under which royalties or commercial and sales-based milestones may be achieved.
Stock-Based Compensation
	Stock-Based Compensation
	The Company recognizes stock-based compensation expense based on the grant date fair value of stock options granted to employees, officers and directors. The Company uses the Black-Scholes option pricing model to determine the grant date fair value as management believes it is the most appropriate valuation method for its option grants. The Black-Scholes model requires inputs for risk-free interest rate, dividend yield, volatility and expected lives of the options. Expected volatility is based upon the weighted average historical volatility data of the Company’s common stock. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. The expected lives for options granted represent the period of time that options granted are expected to be outstanding. The Company uses the simplified method for determining the expected lives of options. The Company estimates the forfeiture rate based on historical data. This analysis is re-evaluated at least annually and the forfeiture rate is adjusted as necessary.
	For awards with graded vesting, the Company recognizes compensation costs based on the grant date fair value of awards on a straight-line basis over the requisite service period, which is generally the vesting period.
	Certain of the employee stock options granted by the Company are structured to qualify as incentive stock options (ISOs). Under current tax regulations, the Company does not receive a tax deduction for the issuance, exercise or disposition of ISOs if the employee meets certain holding requirements. If the employee does not meet the holding requirements, a disqualifying disposition occurs, at which time the Company may receive a tax deduction. The Company does not record tax benefits related to ISOs unless and until a disqualifying disposition is reported. In the event of a disqualifying disposition, the entire tax benefit is recorded as a reduction of income tax expense. The Company has not recognized any income tax benefit for its share-based compensation arrangements due to the fact that the Company does not believe it is more likely than not it will realize the related deferred tax assets.
Comprehensive Loss
	Comprehensive Loss
	Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Changes in unrealized gains and losses on marketable securities represent the only difference between the Company’s net loss and comprehensive loss.
Segment Reporting
	Segment Reporting
	Operating segments are determined based on the way management organizes its business for making operating decisions and assessing performance. The Company has a single operating segment, which is the discovery, development and commercialization of drug products.
Basic and Diluted Loss Per Common Share
	Basic and Diluted Loss Per Common Share
	Basic net loss per share is computed using the weighted average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per common share is computed using the weighted average number of common shares outstanding and the weighted average dilutive potential common shares outstanding using the treasury stock method. However, for the three months ended March 31, 2015 and 2014, diluted net loss per share is the same as basic net loss per share as the inclusion of weighted average shares of unvested restricted common stock and common stock issuable upon the exercise of stock options would be anti-dilutive.
	The following table summarizes outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive:
		March 31,
		2015	2014
	Common stock options	10,123,204	8,179,958
	Unvested restricted common stock	734,758	35,000
Recent Accounting Pronouncements
	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU No. 2014-09, —Revenue from Contracts with Customers (Topic 606), which amends the guidance for accounting for revenue from contracts with customers. This ASU supersedes the revenue recognition requirements in ASC Topic 605, and creates a new Topic 606, Revenue from Contracts with Customers. This guidance is effective for fiscal years beginning after December 15, 2016, with early adoption not permitted. Two adoption methods are permitted: retrospectively to all prior reporting periods presented, with certain practical expedients permitted; or retrospectively with the cumulative effect of initially adopting the ASU recognized at the date of initial application. In April 2015, the FASB proposed a one year deferral of the effective date of this standard to annual periods ending after December 15, 2017, along with an option to permit companies to early adopt the standard for annual periods beginning after December 15, 2016. The Company has not yet determined which adoption method it will utilize or the effect that the adoption of this guidance will have on its consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15, —Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. This ASU is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years ending after December 15, 2016, with early application permitted. The Company has not yet determined the effect that the adoption of this guidance will have on the disclosures included in its consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2015
Summary of Significant Accounting Policies
Summary of the outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive
		March 31,
		2015	2014
	Common stock options	10,123,204	8,179,958
	Unvested restricted common stock	734,758	35,000

Cash_Cash_Equivalents_and_Mark1

Cash, Cash Equivalents and Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2015
Cash, Cash Equivalents and Marketable Securities
Summary of cash, cash equivalents and available-for-sale marketable securities
		March 31, 2015
		Cost		Unrealized		Unrealized			Fair
				gains		losses			value
	Cash and cash equivalents:
	Cash and money market funds (Level 1)	$	21,720	$	—	$	—		$	21,720
	Corporate debt securities due within 3 months of date of purchase (Level 2)	11,535		—		—			11,535
	Total cash and cash equivalents	$	33,255	$	—	$	—		$	33,255
	Marketable securities:
	Corporate debt securities due within 1 year of date of purchase (Level 2)	43,345		11		(5		)	43,351
	Total cash, cash equivalents and marketable securities	$	76,600	$	11	$	(5	)	$	76,606
		December 31, 2014
		Cost		Unrealized		Unrealized			Fair
				gains		losses			value
	Cash and cash equivalents:
	Cash and money market funds (Level 1)	$	45,004	$	—	$	—		$	45,004
	Corporate debt securities due within 3 months of date of purchase (Level 2)	1,020		—		—			1,020
	Total cash and cash equivalents	$	46,024	$	—	$	—		$	46,024
	Marketable securities:
	Corporate debt securities due within 1 year of date of purchase (Level 2)	51,662		12		(8		)	51,666
	Total cash, cash equivalents and marketable securities	$	97,686	$	12	$	(8	)	$	97,690

Property_and_Equipment_Tables

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2015
Property and Equipment
Schedule of property and equipment
		March 31,			December 31,
		2015			2014
	Laboratory equipment	$	12,217		$	12,217
	Leasehold improvements	4,988			4,988
	Computers and software	3,126			3,126
	Furniture and fixtures	1,176			1,176
		21,507			21,507
	Less accumulated depreciation and amortization	(20,652		)	(20,483		)
		$	855		$	1,024

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation
Summary of stock option activity
		Shares		Weighted average
				exercise price
				per share
	Outstanding at January 1, 2015	8,829,343		$	6.17
	Options granted	1,693,686		2.39
	Options exercised	—		—
	Options cancelled	(399,825	)	9.14
	Outstanding at March 31, 2015	10,123,204		$	5.42
	Exercisable at March 31, 2015	5,305,790		$	6.45
Summary of unvested restricted share activity
		Shares		Weighted
				average
				grant date
				fair value
				per share
	Outstanding at January 1, 2015	744,514		$	3.65
	Vested	(9,756	)	4.1
	Granted	—		—
	Forfeited	—		—
	Outstanding at March 31, 2015	734,758		$	3.65
Schedule of weighted average assumptions used to estimate fair value of each employee stock option award
		Three Months
		Ended March 31,
		2015		2014
	Risk-free interest rate	1.77	%	1.84	%
	Expected life in years	6.25		6.25
	Volatility	101	%	104	%
	Expected dividend yield	—		—
Schedule of stock-based compensation expense
		Three Months
		Ended March 31,
		2015			2014
	Stock-based compensation expense by type of award:
	Employee stock options	$	1,508		$	2,529
	Restricted stock	202			57
	Total stock-based compensation expense	$	1,710		$	2,586
	Effect of stock-based compensation expense by line item:
	Research and development	$	981		$	1,131
	General and administrative	729			1,455
	Total stock-based compensation expense included in net loss	$	1,710		$	2,586
Schedule of unrecognized stock-based compensation expense
	Unrecognized stock-based compensation expense as of March 31, 2015 was as follows (dollars in thousands):
		Unrecognized			Weighted
		stock			average
		compensation			remaining
		expense			period
					(in years)
	Employee stock options	$	13,821		2.79
	Restricted stock	2,343			3.19
	Total	$	16,164		2.85

Other_Accrued_Liabilities_Tabl

Other Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Other Accrued Liabilities
Schedule of other accrued liabilities
	Other accrued liabilities as of March 31, 2015 and December 31, 2014 consisted of the following (in thousands):
		March 31,		December 31,
		2015		2014
	Compensation and benefits	$	2,605	$	3,852
	Professional fees	1,696		1,285
	Other	1,107		1,040
		$	5,408	$	6,177

Term_Loans_Tables

Term Loans (Tables)	3 Months Ended
	Mar. 31, 2015
Term Loans
Schedule of future principal payments under the GECC and Oxford Term Loans
	Future principal payments under the GECC and Oxford Term Loans as of March 31, 2015 were approximately as follows (in thousands):
	Years ending December 31,
	2015	$	6,913
	2016	4,607
	Total principal payments	11,520
	Less current portion	(9,221		)
	Long term portion	$	2,299

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details 2)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Common stock options
Anti-dilutive securities
Outstanding securities not included in the computation of diluted net income (loss) per common share as their inclusion would be anti-dilutive (in shares)	10,123,204	8,179,958
Restricted stock
Anti-dilutive securities
Outstanding securities not included in the computation of diluted net income (loss) per common share as their inclusion would be anti-dilutive (in shares)	734,758	35,000

Cash_Cash_Equivalents_and_Mark2

Cash, Cash Equivalents and Marketable Securities (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Cash, Cash Equivalents and Marketable Securities
Cash, cash equivalents and marketable securities, unrealized gains	11	12
Cash, cash equivalents and marketable securities, unrealized losses	-5	-8
Cost
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	33,255	46,024
Total cash, cash equivalents and marketable securities	76,600	97,686
Fair value
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	33,255	46,024
Total cash, cash equivalents and marketable securities	76,606	97,690
Corporate debt securities due within 1 year of date of purchase
Cash, Cash Equivalents and Marketable Securities
Marketable securities, Unrealized gains	11	12
Marketable securities, Unrealized losses	-5	-8
Corporate debt securities due within 1 year of date of purchase | Cost
Cash, Cash Equivalents and Marketable Securities
Marketable securities	43,345	51,662
Corporate debt securities due within 1 year of date of purchase | Fair value | Level 2
Cash, Cash Equivalents and Marketable Securities
Marketable securities	43,351	51,666
Cash and money market funds | Cost
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	21,720	45,004
Cash and money market funds | Fair value | Level 1
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	21,720	45,004
Corporate debt securities due within 3 months of date of purchase | Cost
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	11,535	1,020
Corporate debt securities due within 3 months of date of purchase | Fair value | Level 2
Cash, Cash Equivalents and Marketable Securities
Cash and cash equivalents	11,535	1,020
Maximum | Corporate debt securities due within 1 year of date of purchase
Cash, Cash Equivalents and Marketable Securities
Maturity period from date of purchase to classify an investment as marketable securities	1 year	1 year
Maximum | Corporate debt securities due within 3 months of date of purchase
Cash, Cash Equivalents and Marketable Securities
Maturity period from date of purchase to classify an investment as cash and cash equivalents	3 months	3 months

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Property and Equipment
Property and equipment, gross	$21,507		$21,507
Less accumulated depreciation and amortization	-20,652		-20,483
Property and equipment, net	855		1,024
Depreciation and amortization	169	168
Laboratory equipment
Property and Equipment
Property and equipment, gross	12,217		12,217
Leasehold improvements
Property and Equipment
Property and equipment, gross	4,988		4,988
Computers and software
Property and Equipment
Property and equipment, gross	3,126		3,126
Furniture and fixtures
Property and Equipment
Property and equipment, gross	$1,176		$1,176

Stockholders_Equity_Details2

Stockholders' Equity (Details2) (USD $)	1 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Jul. 31, 2014	Mar. 31, 2015	Sep. 30, 2014
Common Stock
Number of votes per share that common stockholders are entitled to receive		1
At-The-Market Issuance Sales Agreement
Common Stock Issued
Maximum aggregate offering price	$50	$27
Number of shares sold by the entity			5,679,685
Value of shares sold by the entity			23
Weighted average selling price (in dollars per share)			$4.05
Net proceeds after deducting commissions and other transactions costs			$22.50
MLV & Co. LLC | Maximum | At-The-Market Issuance Sales Agreement
Common Stock Issued
Percentage of gross proceeds payable as commission		3.00%

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		1 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Jan. 31, 2015	Dec. 31, 2014
Common stock options
Shares
Outstanding at the beginning of the period (in shares)	8,829,343		8,829,343
Options granted (in shares)	1,693,686
Options cancelled (in shares)	-399,825
Outstanding at the end of the period (in shares)	10,123,204
Exercisable at the end of the period (in shares)	5,305,790
Weighted average exercise price
Outstanding at the beginning of the period (in dollars per share)	$6.17		6.17
Options granted (in dollars per share)	$2.39
Options cancelled (in dollars per share)	$9.14
Outstanding at the end of the period (in dollars per share)	$5.42
Exercisable at the end of the period (in dollars per share)	$6.45
Additional disclosures
Total cash received from stock option exercises	$0	$0.80
Weighted-average grant date fair value of options (in dollars per share)	$1.92	$5.02
Weighted average assumptions used to estimate fair value of each employee stock option award
Risk-free interest rate (as a percent)	1.77%	1.84%
Expected life in years	6 years 3 months	6 years 3 months
Volatility (as a percent)	101.00%	104.00%
Restricted stock
Additional disclosures
Total fair value of restricted stock vested during the period	$0.10	$0.10
Shares
Outstanding at the beginning of the period (in shares)	744,514		744,514
Vested (in shares)	-9,756
Outstanding at the end of the period (in shares)	734,758
Weighted average grant date fair value
Outstanding at the beginning of the period (in dollars per share)	$3.65		3.65
Vested (in dollars per share)	$4.10
Outstanding at the end of the period (in dollars per share)	$3.65
2006 Stock Plan
Stock-based compensation expense
Shares reserved for issuance			11,600,000	10,300,000
Increase in number of shares reserved for issuance			1,300,000
Percentage of outstanding shares of common stock used to compute annual increase in number of shares reserved for issuance			5.00%
Shares available for future issuance	1,261,136
2006 Stock Plan | Common stock options | Maximum
Stock-based compensation expense
Expiration period	10 years
Vesting period	4 years

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Stock-based compensation expense
Stock-based compensation expense	$1,710	$2,586
Research and development
Stock-based compensation expense
Stock-based compensation expense	981	1,131
General and administrative
Stock-based compensation expense
Stock-based compensation expense	729	1,455
Common stock options
Stock-based compensation expense
Stock-based compensation expense	1,508	2,529
Restricted stock
Stock-based compensation expense
Stock-based compensation expense	$202	$57

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 3) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Unrecognized stock-based compensation expense
Unrecognized stock compensation expense	$16,164
Weighted average remaining period	2 years 10 months 6 days
Common stock options
Unrecognized stock-based compensation expense
Unrecognized stock compensation expense	13,821
Weighted average remaining period	2 years 9 months 15 days
Restricted stock
Unrecognized stock-based compensation expense
Unrecognized stock compensation expense	$2,343
Weighted average remaining period	3 years 2 months 9 days

Other_Accrued_Liabilities_Deta

Other Accrued Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Other Accrued Liabilities
Compensation and benefits	$2,605	$3,852
Professional fees	1,696	1,285
Other	1,107	1,040
Other accrued liabilities	$5,408	$6,177

CoDevelopment_and_License_Agre1

Co-Development and License Agreements (Details) (License Arrangement)	31-May-14
	item
License Arrangement
Co-Development and License Agreements
Number of lead candidates	2
Number of lead candidates to be developed	1

Term_Loans_Details

Term Loans (Details) (USD $)	1 Months Ended		3 Months Ended		9 Months Ended	1 Months Ended			7 Months Ended	12 Months Ended
	Jan. 31, 2014	Mar. 31, 2013	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Apr. 30, 2014	31-May-11	Mar. 31, 2011	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2014
	payment				payment		payment			payment
Future principal payments under the GECC and Oxford Term Loans
2015			$6,913,000
2016			4,607,000
Total principal payments			11,520,000
Less current portion			-9,221,000								-9,214,000
Long term obligation			2,299,000								4,607,000
GECC Term Loan
Term Loans
Proceeds from term loans		12,900,000
Annual interest rate on term loan (as a percent)			9.75%
Number of equal monthly payments of principal plus accrued interest	30				9
Exit fee to be paid			788,000
Interest expense recognized			400,000	600,000
Transaction and exit fees and expenses recognized in interest expense			100,000	100,000
Future principal payments under the GECC and Oxford Term Loans
Total principal payments		22,500,000			22,500,000
GECC Term Loan | Maximum
Term Loans
Amount of equipment financing allowed under covenants without any restriction			4,000,000
Oxford Term Loan
Term Loans
Proceeds from term loans								2,000,000
Annual interest rate on term loan (as a percent)			13.35%
Number of equal monthly payments of principal plus accrued interest							36
Interest expense recognized			13,000	20,000
Number of equal monthly payments of principal plus accrued interest										36
Full payment of the original loan						2,000,000
Principal amount of debt issued									600,000
Administrative, legal fees and expenses paid			108,000
Oxford Term Loan | Maximum
Term Loans
Additional amount that the Company may fully utilized in equipment financing										600,000
Oxford Term Loan | Minimum
Term Loans
Amount of debt assumption from acquisitions requiring prior written consent under covenants			$2,000,000

Subsequent_Events_Detail

Subsequent Events (Detail) (Subsequent event, Public Offering, Common stock, USD $)	1 Months Ended
In Millions, except Share data, unless otherwise specified	Apr. 30, 2015
Subsequent Events
Value of shares sold by the entity	$44.30
Sale of common stock (in shares)	25,300,000
Sale of common stock (in dollars per share)	$1.75
Net proceeds from issuance of common stock	$41.80
Largest Shareholder Members Of Board Of Directors And Entities Affiliated With Directors
Subsequent Events
Sale of common stock (in shares)	7,257,142
Underwriters Option
Subsequent Events
Sale of common stock (in shares)	3,300,000